Metal alloy.



"r'rn ra HUGH S. COOPER, OI CLEVELAND, OHIO, ASSIGNOR TO THE ELEG'IRO METALS PRODUCTS v CUMPANY, OF CLEVELAND, OHIO.-

nn'rar. armor.

Specification of Letters Patent.

Patented Dec. 4L, 191W.

no mea application filed January at, 1am, Serial No. vaas a Renewed October a, raw. aerial at.

WWME.

To all whom it may concern: Be it known that l, Home S. Coornr, a citizen of the United States, residmg. at Cleveland, in the county of Cuyahoga and State of Ohio, have invented certain new and useful Improvements in Metal Alloys, of which the following is a specification. lhis invention relates to an improvement in metal alloys, the object being to provide. use as a contact for a magneto as the are a new and useful. substitute, for platinum for use in the electrical art. Platinum is used extensively for contact points in induction coils, magnetos, master vibrators,-

and high-frequency apparatus, and a practical commercial substitute therefor must possess substantially the same hard and wearing properties, high-melting point electrical conductivity, ductility and malleability, and be non-oxidizing. l have discovered that these requirements are met by alloying gold and silver in substantially v equal proportions with a small percentage of another 'metal adapted to harden and raise the melting point thereof. The metals which may be added for this purpose may consist of osmium, niobium, rhodium, ruthenium, palladium, cobalt, molybdenum, tantalum, chromium, tungsten, thorium,

titanium, vanadium, zirconium, or a combination of these metals. Osmium is mentioned first as is preferred as about four per cent. of this metal in the alloy produces a fine hard metal which does not oxidize on the surface when used as an electrical contact.'- Specifically stated, an alloy consisting of four per cent. of osmium, forty-eight per cent. of silver, and forty-eight percent. of gold, is characterized by a high melting point, great hardness, its malleability and ductility so as to be easily worked, electrical conductivity similar to platinum, and by its low cost compared with platinum. The electrical conductivity of silver is rated at about 100, and gold 72, but l have discovered that a combination of gold and silver in approximately equal produces an alloy with an electncal conductivity of onlyabout 15, or about one point less than platinum. Where the proportions of gold or silver vary from the foregoing by anincrease or decrease of five per cent. or more, the alloy is not especially suited for at the point of contact increases to such an extent that a regular series of sparks can "Inotgbe obtained.

iillhe production of my improved alloy takes place preferably in an electric furnace and in an-atmosphere free from oxidizing gases, and care must be exercised to have the metals free from impurities such as copper, silicon, etc., as thesetend tooxidize, thus making the product useless for electrical purposes. a

What if claim is:

1. A metal alloy consisting of gold, silver and osmium having a high melting point and great hardness and possessing ductile and malleable properties and an electrical conductivity similar to platinum.

2. A metal alloy consisting of gold and silver in approximately equal proportions and a relatively small percentage of osmium.

3. A metal alloy consisting of gold and silver with the addition'of approximately four per cent. of osmium.

4. An electrical contact member made of an alloycomposedin a preponderating degree of gold and silver and a relatively small proportion of osmium adapted to R. ]B. Mosnr, Gno. E. Karenina.

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